Functional Abdominal Pain (FAP) of childhood is a disorder for which there is no identifiable organic etiology, yet which is associated with illness behavior of significant personal and societal cost. Prior research suggests that responses from the environment contribute to such illness behavior and dysfunction through social learning processes, as when parents respond solicitously to child symptom complaints, e.g., with increased attention and relief from responsibility. Catastrophizing (CAT), an overly negative appraisal in which pain is seen as signifying a high degree of threat or harm, is known to amplify the experience and expression of pain, but the relationship of CAT to social learning processes has not been adequately examined. In the present proposal, we focus on CAT cognitions on the part of significant others, specifically, mothers of children with FAP. Mothers' CAT about their child's pain may lead them to interpret pain behaviors exhibited by their child as indicative of harm, damage or threat to the well-being of the child, and thus may increase the likelihood that they intervene by taking action to reduce demands on the child or allay the child's discomfort via solicitous responding, thereby encouraging illness behavior. This project aims to: 1) assess feasibility of a symptom provocation and behavioral observation paradigm designed to examine FAP child pain behavior and maternal response, and 2) determine whether the association between child pain behavior and maternal solicitousness is mediated by maternal CAT. Seventy-five children with FAP aged 8-12 and their mothers will serve as participants. Mothers will complete measures designed to assess generalized anxiety, CAT cognitions regarding their child's pain, and typical responses to their child's symptom complaints. Children will rate their pain intensity and then participate in a safe and validated water load procedure intended to simulate abdominal discomfort; in so doing, they will be asked to drink water until they are completely full, not to exceed 15 minutes. Next, children will clean a room much as they would at home (e.g., put away books and toys and make a bed). Children will be instructed to take the lead in this task but may ask their mother for assistance; similarly, mothers may offer assistance with or without a request from their child. The water load procedure and ensuing cleaning task will be videotaped, affording behavioral coding of child pain behavior and maternal response. Post-task questionnaires will assess acceptability of the paradigm. Findings will lay the groundwork for conducting a larger study using this methodology to explore the cognitive, affective, and behavioral pathways by which FAP may be maintained. This in turn will help to determine appropriate targets for intervention for children with FAP and their families, with the aim of reducing associated dysfunction and distress.